This invention relates generally to reciprocating plunger pumps for pumping liquids and more particularly to an improved liquid end valve assembly wherein the suction inlet assembly and discharge outlet assembly are designed and constructed to provide a reciprocating plunger pump with improved pumping capacity.
Conventional T-head liquid end valve assemblies wherein the suction inlet valves and discharge outlet valves are disposed in heads so that the fluid flow paths therethrough were perpendicular to the axis of the pumping chambers in the cylinder heads of the reciprocating plunger pumps, experienced failures due to the stress concentrations created in the liquid end of the reciprocating plunger pumps.
This is more fully explained and set forth in U.S. Pat. No. 3,114,326 in respect of these problems at high operating pressures.
In U.S. Pat. No 3,114,326 a construction is shown for eliminating these stress concentrations at the intersecting bores by providing a liquid end having suction inlet valves and discharge outlet valves wherein the fluid flow therethrough is in alignment with the longitudinal axis of the respective associated pumping chambers. Similar efforts are shown in U.S. Pat. Nos. 3,106,169, 3,260,217, 3,309,014 and 3,702,624.
The present invention also has an aligned and coaxial suction inlet assembly and discharge outlet assembly for each respective liquid end valve assembly so that the associate suction inlet valve head and discharge outlet valve head are movable substantially parallel to and/or coaxial with the associated plunger of the multi-plunger reciprocating pump to provide improved inlet characteristics for the suction inlet assembly, maximum free flow of fluid being pumped therethrough and natural venting of air or gases through the discharge outlet assembly, and which further provides a higher compression ratio for the pumping chamber.
The suction inlet assembly is formed in two parts and therefore can be readily machined with relatively large passages therethrough to provide maximum inlet flow area with minimum radial space requirements. The two part element can be assembled and joined so as to provide a tapered outer surface for removably connecting the suction inlet assembly in the associate cylindrical containing parts of the valve assembly in which it is mounted by a taper driven fit.
The discharge outlet assembly also has a tapered outer surface for removably connecting the discharge outlet assembly into assembled position in the annular cylindrical containing parts of the associated valve assembly in which it is mounted also by a taper driven fit.
The construction of the valve assembly and the tapered connection for the suction inlet assembly and discharge outlet assembly are less costly to manufacture, simplify repair of the suction inlet valve or discharge outlet valve in the event of failure, and permit independent gasketing of critical areas of the valve assembly against the high pressure of the fluid being pumped.